Crude oil is plunging as US inventories swell to a record

West Texas Intermediate crude oil trades down 5.2% at $50.36 per barrel as of 2:21 p.m. ET after the latest inventory data from the Department of Energy showed supplies rose by 8.21 million barrels to 528.4 million barrels. That's the highest since record keeping began in 1982, according to Bloomberg. Wednesday's selling has WTI on track to close at its lowest level since the end of November.

WTI has had trouble breaking out above the $55 level despite reports that OPEC compliance with its agreed upon production cut is nearing 100%. Crude oil prices began rallying in mid-November on speculation OPEC would cut production at its November 30 meeting, and prices continued higher into early 2017 as both OPEC and non-OPEC producers agreed to cut production to help alleviate record oil inventories.

But inventories have continued to swell in the US, and that has kept a lid on prices.